The invention relates generally to coated polymer dielectric films and specifically to polymer dielectric films coated with inorganic materials.
Polymers with high resistivity, high permittivity, low dissipation factors and high electric field breakdown strengths (Vb) have important applications as dielectrics in electronic devices, such as a capacitor. The electronic industry is cost- and performance-driven, and constantly increasing demands are made on materials to lower cost, and improve their reliability and performance. Polymer based devices have long been of interest because manufacturing technologies associated with extrusion or solution casting of polymer films can be readily combined with thin film metallization techniques, to yield devices that are flexible and economical, and which can be manufactured into very large electronic devices.
Polymer based electronic devices have been used for many power electronics and pulse power applications, because of their inherent low dielectric losses, excellent high frequency response, low dissipation factor (DF), low equivalent series resistance (ESR), and high voltage capabilities. However, most of the dielectric polymers are characterized by low energy densities (<5 J/cc), and/or have low breakdown strength (<450 kV/mm), which may limit the operating voltage of an electronic device. Other disadvantages are relating to thermal stability and reduced lifetime, for example. In order to achieve high energy density, it may be desirable to have both high dielectric constant and high breakdown strength. A trade-off between these two properties may not be advantageous. Most dielectric polymers that exhibit high breakdown strength have a relatively low dielectric constant.
There is a need for polymer materials that would address the aforementioned problems and meet the current demands of electronics industry applications. Therefore, it is important to devise a method and formulate a structure including polymer materials that results in a considerably high dielectric constant and relatively high breakdown strength. Further, there is a need for structures and materials that are stable at humid environments, for the ease of handling while forming polymer based electronic devices.